Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 91: Poster Session: Spintronics / Magnetic Semiconductors / Transport
HL 91.5: Poster
Donnerstag, 29. März 2012, 16:00–19:00, Poster D
Electron spin dynamics in wurtzite GaN — Jan Heye Buß, Jörg Rudolph, Arne Schaefer, •Jago Döntgen, and Daniel Hägele — AG Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Germany
The semiconductor GaN is well established in modern optoelectronics and is considered a candidate for semiconductor spinelectronics due to its small spin-orbit splitting. However, electron spin lifetimes were found to hardly exceed 50 ps at room temperature [1, 2] whereas GaAs with its larger spin-orbit splitting shows RT lifetimes of about 200 ps. The symmetry of wurtzite GaN is found to cause a k-linear dependence of the effective magnetic field (effective Rashba field) in the conduction band whereas cubic semiconductors show a k3-dependence. As a direct consequence of the linear Rashba field we observe by time-resolved Kerr-rotation spectroscopy an anisotropic spin relaxation tensor [3], and a weaker dependence of spinlifetimes on temperature [2] and doping density [4] as compared to e.g. cubic GaAs. All results are quantitatively explained without any fitting parameter by a newly derived analytic expression for Dyakonov-Perel spin relaxation in wurtzite semiconductors [3,4].
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J. H. Buß et al., Phys. Rev. B 81, 155216 (2010)
J. H. Buß et al., Appl. Phys. Lett. 95, 192107 (2009)
J. H. Buß et al., Phys. Rev. B 84, 153202 (2011)